Level adjusting mechanism for free arm sewing machine



Sept. 23, 1969 D. E. MAYNARD 3,468,589

LEVEL ADJUSTING MECHANISM FOR FREE ARM SEWING MACHINE Filed Jan. 5. 1968 2 Sheets-Sheet '1 Douaans MDYJQAQD I N VEN TOR.

Sept. 23, 1969 k D. E. MAYNARD LEVEL ADJUSTING MECHANISM FOR FREE ARM SEWING MACHINE Filed Jan. 5, 1968 2 Sheets-Sheet 5.-

6G 95 2a 2a LIE 63 6o 64" 24 24 I 3O 30 l INVENTORJ D0064 4s 1;. M4 yum? BY M 1 firmed Ev United States Patent 3,468,589 LEVEL ADJUSTING MECHANISM FOR FREE ARM SEWING MACHINE Douglas E. Maynard, Los Angeles, Calif. (13216 Leach Sh, Sylmar, Calif. 91342) Filed Jan. 5, 1968, Ser. No. 696,042 Int. Cl. A47b 81/00; D05b 75/00 US. Cl. 312-29 14 Claims ABSTRACT OF THE DISCLOSURE An apparatus facilitating level adjustment of a free are sewing machine inside a cabinet. Grooved slide blocks engage slide bars attached to the cabinet walls and support therebetween a horizontal sewing machine platform. Constant force springs connect the blocks to the upper portion of the cabinet. Spring biased bolts extend through the blocks and engage holes in the slide bars, which holes are located to permit the platform to be positioned with the sewing machine at a storage, free arm sewing, or standard sewing level. The bolts may be disengaged from the slide bars by means of bracket members which pivot, under control of a latch release bar or cord, to pull the bolts from the holes.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to an apparatus for adjusting the level of a free arm sewing machine. More particularly, the invention relates to an apparatus adapted to be mounted inside a conventional sewing machine cabinet and comprising a platform adapted to receive a free arm sewing machine and to be slidingly positionable to a selectable level to permit storage, free arm sewing or normal sewing.

Description of the prior art A free arm sewing machine is one in which the bobbin mechanism is housed in a free arm extending horizontally beneath the position of the vertically movable sewing machine needle. Such a free arm sewing machine permits sewing of small circular items as, for example, the hem of a sleeve. Such a hem is difiicult to sew on a conventional sewing machine because only the portion of the sleeve being sewn can fit beneath the needle, whereas the remainder of the sleeve must be folded back away from the needle. In a free arm sewing machine, that section of a circular item diametrically opposite the point being sewn may be disposed beneath the free arm.

In conventional free arm sewing machine cabinets, the sewing machine is mounted to the cabinet to pivot about a horizontal axis from a first position in which the machine is stored on its side within the cabinet to a second position in which the sewing machine extends upwardly from the top sewing surface of the cabinet. In this upright position, the free arm is situated one or more inches above the top surface of the cabinet. While this position is convenient for sewing which requires use of the free arm, it is awkward for standard sewing. For example, if a seam in a long piece of material were to be sewn, the material would drape over the free arm onto the top of the cabinet. Such a situation complicates accurate sewing and is annoying to the person operating the machine.

For optimum utilization of a. free arm sewing machine, the cabinet housing the machine should allow the machine to be situated at one of three levels: stored or completely enclosed within the cabinet; 2 free arm sewing position at which the free arm is raised one or more inches above the top level of the cabinet; and a standard 3,468,589 Patented Sept. 23, 1969 sewing position in which the top surface of the free arm is coplanar with the top of the cabinet. In the past, such a cabinet has not been available. Rather, as noted hereinabove, prior art sewing machine cabinets were adapted to permit the sewing machine to pivot between one of two positions, a storage position and a free arm sewing position. Clearly, hinge mechanisms typical of the prior art are inappropriate for the three level operation optimally desired.

While movable horizontal sewing machine support platforms have been suggested in the past, generally these have been bulky and have involved complicated latch mechanism difiicult to install on a standard cabinet and even more difiicult for a housewife to operate. Further, when the latch mechanism was released, the platform had to be moved vertically under the full effective weight of the sewing machine.

To overcome these limitations of prior art free arm sewing machine cabinets, there is disclosed herein a level adjusting mechanism which readily may be installed in an existing cabinet and which permits the level of a free arm sewing machine to be adjusted easily between stored, free arm sewing and standard sewing positions. The mechanism includes springs to counterbalance the weight of the sewing machine and a novel latch release mechanism which is both inexpensive and easy to operate.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a mechanism for adjusting the level of a free arm sewing machine. The mechanism comprises a pair of slide bars adapted for vertical attachment inside a standard sewing machine cabinet in opposite parallellism. Suspended between the slide bars is a horizontal platform on which the sewing machine is mounted. The platform is attached to a pair of spaced grooved sliding blocks which engage their respective slide bars. The sliding blocks are supported by a pair of preferably constant-force springs depending from the upper portion of the slide bars or the cabinet. The springs counterbalance the weight of the sewing machine and permit vertical motion of the platform and sewing machine to preselected levels with a minimum of force.

Each of the sliding blocks is provided with a springbiased bolt adapted to engage its slide bar via holes located in the slide bar at levels appropriate for sewing machine storage, free arm sewing, or standard sewing. The bolt may be disengaged from the slide bar holes by means of a novel latch mechanism comprising a substantially right angle bracket member slotted adjacent the right angle to permit mounting of the bracket to the sliding block by means of a screw through the slot. Further, the bracket contains a notch at its lower end for straddling the shank of the spring-biased bolt. A latch release bar extends horizontally between the pair of latch release brackets. The pair of bolts may be simultaneously released from the holes merely by pressing the latch release bar. In a second embodiment, the latch release bracket members are operated via a cord and pulley system whereby the bolts may be disengaged by pulling on a ring attached to the end of a cord.

The inventive apparatus also includes a platform the length of which is adjustable to fit a cabinet of any size.

Thus, it is an object of the present invention to provide a level adjusting mechanism for a free arm sewing machine.

Another object of the present invention is to provide a mechanism which may be installed within an existing sewing machine cabinet to permit the level of a sewing machine to be adjusted.

Yet another object of the present invention is to provide a level adjusting mechanism whereby the level of a free arm sewing machine readily may be changed from a storage position to either a free arm or a standard sewing position.

A further object of the present invention is to provide a sewing machine level adjusting mechanism comprising a horizontal platform disposable betwen a pair of slide bars which may be attached vertically within a sewing machine cabinet.

Another object of the present invention is to provide a vertically adjustable sewing machine platform adjustable to preselected levels and including counter-balance springs to permit easy vertical motion.

Yet a further object of the present invention is to provide a sewing machine level adjusting mechanism including a novel latch having a pair of spring-biased bolts which may be disengaged from mating holes by means of substantially right-angle bracket members.

Still a further object of the present invention is to provide a free arm sewing machine level adjusting mechanism comprising a spring-loaded platform vertically positionable to preselected locations, at which locations bolt members engage holes in vertical slide bars. The bolt members may be disengaged by a novel release mechanism.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE la is a perspective view of a typical free arm sewing machine cabinet, including the inventive level adjusting mechanism. The cabinet is shown closed with the sewing machine indicated in phantom in its stored position;

FIGURE lb is a fragmentary front elevation view of the free arm sewing machine cabinet of FIGURE la, with the sewing machine illustrated in the free arm sewing position;

FIGURE is a fragmentary front elevation view, in partial section, of the free arm sewing machine cabinet illustrated in FIGURE la. The inventive level adjusting mechanism is illustrated supporting the sewing machine in the standard sewing position;

FIGURE 2 is an enlarged fragmentary front elevation view, in partial section, illustrating various details of the inventive level adjusting mechanism also shown in FIG- URE 1c. The embodiment illustrated utilizes a latch release bar mechanism;

FIGURE 3 is a fragmentary plan view, in partial section, as seen from the top in FIGURE 2;

FIGURE 4 is an enlarged sectional view of the latch portion of the inventive level adjusting mechanism, as seen generally along the line 44 of FIGURE 2;

FIGURE 5 is a fragmentary front elevation view, in partial section, of the inventive level adjusting mechanism latch, as seen generally along the line 5-5 of FIGURE 4;

FIGURE 6 is a top plan View of the sewing machine support platform portion of the inventive level adjusting mechanism. In the embodiment shown, the platform is of adjustable length;

FIGURE 7 is a sectional view of the adjustable length platform, as seen generally along the lines 77 of FIG- URE 6;

FIGURE 8 is a fragmentary front elevation view, in partial section, of another embodiment of the inventive level adjusting mechanism, utilizing a cord and pulley mechanism for latch release; and

FIGURE 9 is a fragmentary perspective view of a portion of the cord and pulley latch release mechanism shown in FIGURE 8.

4 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGURE 1a, there is shown a typical sewing machine cabinet 10 having legs 11, sides 12 and top 13. Cabinet 10 is illustrated in its closed storage position with hinged cover 14 enclosing stored sewing machine 15 (shown in phantom). Cabinet front panel 16 also is shown in the closed or stored position adjacent drawers 17 which may be used for storage of various sewing implements. Cover 14 typically is adapted to rotate about a horizontal axis into the position illustrated in phantom at 14a, thereby providing an extended sewing surface. In addition, front panel 16 is adapted to rotate about a vertical axis into the position shown in phantom at 16a, which position provides support for open cover 14a and which also exposes panel 18 which hides the inventive level adjusting mechanism in the storage position. Note in FIGURE 1a that sewing machine 15, as supported by the inventive level adjusting mechanism, is held upright during storage.

In FIGURE 1b, sewing machine cabinet 10 is illustrated with cover 14 open, the upper surface of cover 14 being parallel to the top sewing surface 19 of cabinet 10. As illustrated, free arm sewing machine 15 is supported by the inventive level adjusting mechanism in the free arm sewing position. In this position, the base 20 of sewing machine 15 is substantially coplanar with sewing surface 19 of cabinet 10. Free arm 15' then may be seen to reside at a location some one or more inches above the sewing surface 19.

Note that, in the free arm sewing position illustrated in FIGURE 1!), the inventive level adjusting mechanism supporting sewing machine 15 is situated at its highest level. In the embodiment shown, panel 18 travels up and down with sewing machine 15 and is situated near the top of cabinet 10. The extent of vertical travel of the inventive level adjusting mechanism may be seen in FIGURE 1b wherein the storage positions of panel 18 and sewing machine 15 are shown in phantom at 18a and 15a respectively; these storage positions correspond to those shown in FIGURE la. In an alternative embodiment, panel 18 may be hinged to cabinet 10 so as to pivot to a horizontal position within the cabinet when sewing machine 15 is in a sewing position.

The standard sewing position of free arm sewing machine 15 is illustrated in FIGURE 10. As shown therein, the inventive level adjusting mechanism has been positioned so that base 20 of sewing machine 15 is supported below the level of sewing surface 19. In particular, sewing machine 15 is situated so that the upper surface of free arm 15' is substantially coplanar with sewing surface 19 of cabinet 10. An insert (not shown), internally contoured to the sewing machine periphery at the free arm level, may be provided to assure a continuous sewing table surface with surface 19.

Note in FIGURE 1c that slide bars 21 are attached respectively to walls 12a: and 12b of cabinet 10. Each of the slide bars 21 contain three vertically spaced holes 22, the function of which is described hereinbelow. Sewing machine support platform 23 extends between sliding blocks 24 which blocks are grooved to engage slide bars 21. Also shown in FIGURE 1c is latch release bar 25 which operates a latch mechanism (described in detail hereinbelow) for maintaining platform 23 at one of the three preselected levels for storage, free arm sewing, or standard sewing.

As may be seen in FIGURE 10, sewing machine 15 in the standard sewing position is situated at a lower level than when positioned at 15b (shown in phantom) for free arm sewing. This difference in level, of course, corresponds to the vertical distance between the upper surface of free arm 15' and the upper surface of base 20 of sewing machine 15. The storage positions of platform 23 and sliding blocks 24 are shown in phantom in FIG- URE 1c at 23:: and 24a, respectively.

Various structural details of the inventive level adjusting mechanism for a free arm sewing machine are illustrated in FIGURE 2. Referring thereto, note that slide bars 21 are secured to walls 12a and 12b of cabinet by any apropriate means such as by screws and/or glue. Slide bars 21 extend downward from top 19 of cabinet 10 for a distance suflicient to insure that platform 23 may be lowered to the storage position at which sewing machine (not shown in FIGURE 2) is enclosed completely within cabinet 10. Slide bars 21 include holes 22 at positions appropriate for maintaining platform 23 at the desired levels for storage, free arm sewing and standard sewing. In particular installation, the actual locations of holes 22 will be chosen by taking into account the vertical dimensions of the particular sewing machine being used.

Platform 23 is suspended between sliding blocks 24 which contain grooves 26 to engage slide bars 21. Sliding blocks 24 each contain a vertically extending hole 27 which receives the lower end of one of springs 28. The upper ends of springs 28 are supported by means of hooks 29 to the upper portion of slide bars 21. Springs 28, which may be of the constant force variety, provide a counterbalance for the weight of sewing machine 15 sup ported on platform 23. Springs 28 thus permit platform 23 together with sewing machine 15 to be raised or lowered with the exertion of very little force.

Extending between sliding blocks 24 is latch release bar 25. Latch release bar is connected at its ends to bracket members 30 which, as will be described in detail hereinbelow, function to disengage bolts from holes 22 in slide bars 21.

Referring to FIGURE 3, a top view showing the inventive level adjusting mechanism installed within cabinet 10, it is seen that upper surface 19 of cabinet 10 contains an opening 31 through which sewing machine 15 projects when in one of the sewing positions. The width of platform 23 corresponds generally to that of opening 31. Platform 23 has a length corresponding generally to the distance between vertical side bars 21, and the ends of platform 23 include notches 32 to clear slide bars 21 and springs 28.

Grooves 26 in sliding blocks 24 engage slide bars 21 and insure that platform 23 will be restricted to purely vertical motion longitudinal of slide bars 21. Each of the sliding blocks 24 is provided with a vertical hole 27 within which a spring 28 is disposed.

Details of the novel latch mechanism used in conjunction with the present invention are best seen in FIG- URES 4 and 5. Referring thereto, it is seen that, disposed within each sliding block 24, is a substantially cylindrical plunger or bolt 33 having a reduced diameter shank 34 provided with an enlarged head 35. Bolt 33 is slidably disposed within hole 36 which extends through lateral wing portion 24' of sliding block 24 adjacent groove 26; hole 36 has an inside diameter slightly larger than the outside diameter of bolt 33. Portion 24 of sliding block 24 is covered partially by a plate 37 having hole 38 through which bolt shank 34 is slidably reciprocable. One end of plate 37 is attached to sliding block 24 by means of screw 39. Disposed within hole 36 is a compressed coil spring 40 which is confined between bolt shoulder 33 and plate 37, and serves to bias bolt 33 toward slide bar 21. Bolt 33 preferably has a somewhat cylindrically shaped end 33" to guide bolt 33 into hole 22 under the force of bias spring 40.

Bracket member or lever bar 30 comprises a substantially Lshaped strip of metal having a generally horizontal section 42' and a generally vertical section 42'. Section 42" is provided with a longitudinally elongate slot 43 adjacent substantially right-angle bend 44 which serves as a fulcrum for lever bracket 30 and bears against plate 37. A retainer screw 45 is fastened to block 24 and extends through both slot 43 in member 30 and a hole 45' in plate 37, and has an enlarged head 45" which serves to retain such assemblage. The lower end of vertical section 42" is bent to form an obtuse angle having an apex generally at 46 and includes a parallel pair of prongs 47 defining an opening or open slot 47 having a Width greater than shank 34 but narrower than the diameter of head 35 of bolt 33; prongs 47 straddle shank 34 and are retained thereon by head 35. Latch release bar 25 is secured to the horizontal member 42 of each latch mechanism for common operation thereof. Thus, when latch release bar 25 is pushed upward manually, bracket member 30 pivots about fulcrum 44 to the position illustrated in phantom at 30a in FIGURE 4. This pivotal motion causes vertical member 42" to pull head 35 of bolt 33 away from plate 37, thereby removing bolt 33 from hole 22. Of course, this disengagement permits sliding block 24 to be moved upward or downward along slide bar 21 to a new position. For example, sliding block 24 may be lowered so that bolt 33 next seats within hole 22, thereby lowering the sewing machine from the free arm sewing to the standard sewing position or, alternatively, to the storage position.

Continuing particular reference to FIGURES 4 and 5, it may be seen that assembly of the latch mechanism is readily accomplished by sequentially inserting bolt 33 into sliding block hole 36, disposing spring 40 about bolt shank 34, securing plate 37 to sliding block 24 by screw 39 with bolt head 35 projecting through plate 37, sliding lever means 30 toward bolt shank 34 for reception thereof by open-ended slot 47, aligning hole 43 approximately with plate hole 45' and securing screw 45 therethrough to block 24.

Referring particularly to FIGURE 4, it should be noted that bolt head 35 forcibly bears against lever portion 42" at all times due to the action of spring 40 between stationary plate 37 and movable bolt 33; accordingly, such spring action maintains the entire lever member 30 snugly against the plate 37 at the points of contact, i.e., fulcrum bend 44 and the ends of prongs 47, and simultaneously maintains the same snug relationship of the upper end of plate 37 against block 24 by means of fulcrum bend 44. Thus, it can be seen that screw 45 performs only a general retention and guidance function for preventing rotation of the lever member 30 about the axis of bolt 33 and preventing lever portion 42" from sliding away from bolt shank 34; accordingly, screw 45 does not rigidly secure plate 37 but is passed therethrough only for convenience, and does not rigidly secure lever portion 42" but is only loosely received by hole 43 therein so as to accommodate the angular disposition of lever portion 42" during levering thereof, as in the manner of a lost motion connection. Of course, screw head 45" is spaced from lever portion 42" to prevent obstruction thereof during such levering movement.

It should be noted further that slot 47, in addition to simplifying assembly as aforesaid, provides a lost motion connection between lever portion 42" and bolt shank 34 to accommodate the effects of rectilinear movement of bolt 33 during rotational movement of lever means 30. In addition, it may be noted that the angular relationship of prong portions 47 to the rest of lever portion 42" facilitates sliding of bolt head 35 on prongs 47 during operation of the lever because the head 35 rides on a preferred slope which eliminates frictional binding.

Also shown in FIGURES 2 and 5 is a preferred installation of the lower end of spring 28. As illustrated, hole 27 extends the entire length of block 24. Extending transversely through block 24, including through hole 27, is rod 48. The lower end 28 of spring 28 loops around rod 48 to support block 24 for free-riding suspension of the blocks 24, platform 23 and the sewing machine when the blocks 24 are not engaged with the sliding bars 21 via the latches.

To facilitate utilization of the inventive level adjusting mechanism in sewing machine cabinets of various widths, platform 23 may be made adjustable in length. In the embodiment illustrated in FIGURES 6 and 7, platform 23' comprises two coplanar members 50 held in parallel spaced apart relationship by transverse strip brackets 51 attached to members 50 as by screws 52. Members 50 preferably are grooved as at 50 and the spacing between members 50 selected to equal the width of tongued members 53. As best illustrated in FIGURE 7, tongues 53' of members 53 seat within grooves 50' of members 50 to permit sliding longitudinal motion of members 53. The extreme ends of members 52 contain notches 54 for clearance of slide bars 21; further, members 53 are attached as by screws 55 to sliding blocks 24.

'In a particular installation, sewing machine 15 is mounted on members 50 positioned directly beneath opening 31 (see FIGURE 3) in top 19 of cabinet 10. Sliding members 53 are extended to the appropriate length. Screws 56 are fastened through brackets 51 into members 53 to insure that members 53 will not subsequently move relative to members 50.

An alternative release mechanism for latch means 30 is shown in FIGURES 8 and 9. In the embodiment shown therein, release bar 25 is replaced by first and second cords 60 and 61, attached respectively to horizontal sections 42' of lever bars 30. Cord 60 is fed via pulleys 63 and 64, depending from platform 23, and is attached to cord 61 by connector 66.

As illustrated in FIGURE 9, cord 61 extends upward fi'om platform 23 and engages pulleys 65 and 66 attached to top 19 of sewing machine cabinet 10. Cord 61 terminates in ring 67. Pulling ring 67 then causes levers 30 to pivot, disengaging bolts 33 from holes 22 in slide bars 21 as aforesaid.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made Without departing from this invention in its broader aspects.

What is claimed is:

1. A device for adjusting the level of a free arm sewing machine within a cabinet, said device comprising:

first and second elongate slide bars adapted to be attached vertically to the walls of said cabinet, each of said bars having a plurality of vertically correspondingly spaced holes;

first and second grooved sliding blocks adapted for vertically slidable engagement with said first and second slide bars respectively;

a platform adapted to support said sewing machine, the ends of said platform being fixedly attached to said sliding blocks for movement therewith between said slide bars; and

latch means for releasably securing said sliding blocks to said slide bars at selectable levels, said latch means comprising:

first and second spring biased bolts extending respectively through said first and second blocks and receivable by selected corresponding ones of said holes in said slide bars; and

first and second substantially L-shaped lever members pivotally attached respectively to said first and second sliding blocks, said members engaging said bolts, whereby pivotal motion of said members disengages said bolts from said holes.

2. The device defined in claim 1 wherein each of said lever members comprises:

an elongate strip having a bend therein forming genreally horizontal and vertical sections, said vertical section terminating in a pair of parallel prongs transversely straddling said bolt in retained relationship therewith; and

said bend is a fulcrum for said lever member.

3. The device defined in claim 2 further comprising:

first and second springs, one end of each of said springs being attached respectively to said first and second sliding blocks, the other end of each of said springs being adapted for fixed attachment to the respective upper end of said first and second slide bars.

4. The device defined in claim 3 wherein said springs exert constant force.

5. The device defined in claim 2 further comprising:

release means for simultaneously pivoting said first and second lever members.

6. The device defined in claim 5 wherein said release means com-prises a manually operable release bar substantially corresponding in length to said platform, the respective ends of said release bar being attached to said horizontal sections of said first and second bracket members.

7. The device defined in claim 5 wherein said release means comprises:

first and second cords respectively attached to said horizontal sections of said first and second lever members, and end of said first cord being joined to said second cord; and

pulley means for guiding said cords along said platform and part of said cabinet, whereby manually pulling said second cord causes said lever members to pivot thereby disengaging said bolts from said holes.

8. The device defined in claim 5 wherein said holes are located in said slide bar to permit selective location of said sewing machine at one of the storage, free arm sewing or normal sewing levels.

9. The device defined in claim 8 wherein said platform comprises:

first and second planar grooved members;

bracket means connecting said grooved members in coplanar, parallel spaced apart relationship; and

first and second planar tongued members adapted for tongue-in-groove mating between and coplanar with said grooved members, said tongue members being longitudinally adjusting positionable relative to said grooved members to adjust the effective length of said platform.

10. The device defined in claim 9 further comprising:

means for connecting said bracket means to said tongued members to maintain said tongued and grooved members at a selected longitudinal position relative to each other.

11. Apparatus adapted for installation in a cabinet to facilitate level adjustment of a sewing machine housed therein, said apparatus comprising:

a pair of elongate slide bars adapted for vertical parallel attachment to opposite walls of said cabinet, said slide bars being provided with a mutually corresponding plurality of vertically spaced holes at selected levels;

a pair of blocks each adapted for vertically slidable engagement with a respective one of said slide bars and defining a transverse hole therethrough in communication with said slide bar;

a platform adapted to support said sewing machine, said platform extending between and secured to said blocks, whereby said platform may be slidingly, horizontally supported between said slide bars; and

a pair of latch means for respectively releasably securing said blocks to said slide bars at such selected levels, each of said latch means comprising:

a plate abutting against said block;

a plunger disposed in said transverse hole in said block and having a shank extending through said plate, said plunger being insertable into said spaced holes in said slide bar;

a spring disposed about said shank within said transverse block hole and compressed between said plunger and said plate to bias said plunger away from said plate; and

a lever bar, said lever bar being bent to form a fulcrum, said bar having a pair of prongs extending from one end and defining an elongate open slot 9 10 for receiving said shank with said prongs in stradsaid cabinet front to a horizontal position within said dling engagement with said shank whereby pivotal cabinet beneath said platform. motion of said lever bar about said fulcrum disengages said plunger from one of said spaced holes. References Clted 12. The apparatus defined in claim 11 further compris- 5 UNITED STATES PATENTS 2,738,248 3/1956 Berker 312-29 a pair of constant force springs, each spring adapted 2 790 689 4/1957 Hubbeu to extend between one of said blocks and the upper end of one of said slide bars. FOREIGN T TS 13. The apparatus defined in claim 11 further compris- 10 509 347 3 1952 Fnmw 1118! 563,532 9/1958 Canada.

release means for simultaneously causing said lever bars to pivot about their respective fulcrums. BOBBY Primary Examiner 14. The apparatus defined in claim 13 further compris- 1 L KOHNEN, Assistant Examiner 15 a panel hingeably attached to said cabinet to pivot US. Cl. X.R.

from a vertical position substantially parallel with 112-217.1 

